Patterns of Inheritance

Question 1

_____________ means identical alleles at a genetic locus

Answer 1

homozygous

Question 2

___________ means two different alleles at a genetic locus

Answer 2

heterozygous

Question 3

________ ______________ two different alleles at two different genetic loci (base pairs) in the same gene

Answer 3

compound heterozygote

Question 4

___________ ____________ means two different alleles at two different genetic loci in different genes

Answer 4

Double heterozygote

Question 5

____________ is the proportion of individuals with a gene mutation who actually express the disease condition. The probability that a genetic variation (or allele) will yield the phenotype at all.

Answer 5

penetrance

Question 6

___________ ___________ is the phenomenon of differing clinical features (phenotype) among individuals carrying the same genotype

Answer 6

variable expressivity

Question 7

____________ effect—high frequency of a gene mutation in a population founded by a small ancestral group

Answer 7

founder effect
(bottle neck effect)

Question 8

Two most common mutations in Tay sachs in the ____________ gene on chromosome 15

Answer 8

TATC (80%) insertion in exon 11
intron 12 splice site alteration
G269Ser in exon 7

Question 9

What are Mendel’s 3 laws?

Answer 9

1. Law of segregation
2. Law of independent assortment
3. Law of dominance

Question 10

Mendelian disorders are ________-gene disorders

Answer 10

single

Question 11

Chromosomal disorders are less often _________ and usually syndromic

Answer 11

inherited

Question 12

In autosomal dominant inheritance the dominant gene is located on an _______________ and each child of an affected parent has a __% risk

Answer 12

autosome
50% risk

Question 13

In autosomal dominant inheritance males and females are affected _____________ and the inheritance pattern is __________ with male to male and female to female inheritance observed

Answer 13

equally
vertical

Question 14

In _____________ ______________ the phenotype of heterozygous is intermediate between heterozygous and homozygous

Answer 14

incomplete dominance

Question 15

In co-dominance the contributions of both alleles are visible in the ____________

Answer 15

phenotype

Question 16

Type of inheritance

Answer 16

AD

Question 17

Disease and inheritance?
- MVP, aorta dilitation, tall - arachnodactyly, scoliosis, lens dislocation and myopia

Answer 17

Marfans -FBN1 gene chromosome 15
autosomal dominant

Question 18

_________ criteria for diagnosing Marfan syndrome

Answer 18

Ghent

Question 19

Inheritance pattern?

Answer 19

AR

Question 20

In autosomal recessive disorders the carrier parents have a _______% chance of having an affected child. Females and males are affected equally. If both parents affected then _____% offspring are affected

Answer 20

25%
100%

Question 21

In autosomal recessive enzymatic diseases the phenotype can be the result of precursor __________ or the ___________ of product

Answer 21

accumulation
absence

Question 22

Type of inheritance?

Answer 22

XR

Question 23

In ________ -_________ ___________ inheritance affected individuals are primarily male with unaffected parents. All female siblings will be carriers and the male offspring of the proband are affected

Answer 23

X-linked recessive

Question 24

Is X-linked inheritance vertical or horizontal?

Answer 24

Neither horizontal or vertical

Question 25

Type of inheritance for the following diseases: Hemophilia A, Duchenne/Becker, Fabry's, Fragile X, spinobulbar muscular atrophy and Lesch-Nyhan syndrome

Answer 25

X-linked recessive

Question 26

Type of inheritance for Duchenne/Becker

Answer 26

X-linked recessive

Question 27

Type of inheritance for Hemophilia A

Answer 27

X-linked recessive

Question 28

Type of inheritance for Fabry's

Answer 28

X-linked recessive

Question 28

Type of inheritance for Fragile X

Answer 28

X-linked recessive

Question 29

Type of inheritance for spinobulbar muscular atrophy

Answer 29

X-linked recessive

Question 30

Type of inheritance for Lesch-Nyhan syndrome

Answer 30

X-linked recessive

Question 31

In _______-__________ ____________ inheritance all female offspring of affected males will carry the mutation (may or may not express the phenotype). No male offspring of affected males will be affected. An affected female has a 50% chance of having an affected child. Nearly all affected individuals have an affected parents.

Answer 31

X-linked dominant

Question 32

Type of inheritance?

Answer 32

X-linked dominant

Question 33

Type of inheritance?

Answer 33

X-linked dominant with male lethality

Question 34

In _____-__________ inheritance only males are affected and there is only male to male transmission with 100% of male offspring from affected parent

Answer 34

Y-linked

Question 35

Type of inheritance?

Answer 35

Y-linked

Question 36

The ______________ regions on the Y chromosome are responsible for Y-linked inheritance

Answer 36

pseudoautosomal (PAR)

Question 37

_____________ inheritance pattern is where female proband has all affected children but male proband has no affected children

Answer 37

mitochondrial

Question 38

Type of inheritance?

Answer 38

mitochondrial

Question 39

Heteroplasmy and homoplasmy are affected by _________ segregation

Answer 39

chance

Question 40

Type of inheritance for the following diseases: LHON, Kearns-Sayre, MELAS, MERRF

Answer 40

mitochondrial

Question 41

Amish, Mennonite and Hutterite communities have founder mutations for _____________ gene and 80 other disorders

Answer 41

glutaric acidemia (GA1)

Question 42

French Canadiens (28 disorders) have founder effects in ___________ syndrome and ___________ type I

Answer 42

Leigh syndrome Tyrosinemia type I

Question 43

Which disorders should be considered when inheritance is linked through the female line?

Answer 43

XLD, XLR and mitochondrial

Question 44

Mendelian law of _____________ is violated by uniparental disomy

Answer 44

segregation

Question 45

Mendelian law of _______ ____________ is violated by genes closely linked on the same chromosome

Answer 45

independent assortment

Question 46

Mendelian law of _____________ is violated by co-dominance and incomplete dominance

Answer 46

dominance

Question 47

Type of inheritance?

Answer 47

XLR

Question 48

Type of inheritance?

Answer 48

XLR with homozygous mom

Question 49

Type of inheritance?

Answer 49

AD

Question 50

Type of inheritance?

Answer 50

YL

Question 51

Type of inheritance?

Answer 51

XLR

Question 52

Type of inheritance?

Answer 52

AD

Question 53

Type of inheritance?

Answer 53

AR

Question 54

For the sequence below, where the capital letters are an exon and the lower case letters are intronic, identify the canonical splice acceptor and splice donor site: t t t a t t t c c a g T T G A A T C T T T C T G T A A C G T T A A C T G C T T C C A G g t a a g c c t g

Answer 54

gtag GU 5 splice donor AG 3 splice acceptor

Question 55

If the highlighted T* is c.151, write the HGVS nomenclature if the bolded and underlined G** is changed to an A: t t t a t t t c c a g T* T G** A A T C T T T C T G T A A C G T T A A C T G C T T C C A G g t a a g c c t g

Answer 55

c.153G>A

Question 56

If the highlighted T is c.151, write the HGVS nomenclature if the bolded and underlined base pairs*** are deleted: t t t a t t t c c a g T T G ***A A T*** C T T T C T G T A A C G T T A A C T G C T T C C A G g t a a g c c t g

Answer 56

c. 154_156delAAT or c. 154_156del

Question 57

If the highlighted T is c.151, write the HGVS nomenclature if 3 base pairs, “A-C-T” are inserted between the bolded and underlined base pairs: t t t a t t t c c a g T T G A A T C ***T T T C T G T A A C G T T A A C T G C T T C C A G g t a a g c c t g

Answer 57

c. 157insACT

Question 58

If the highlighted T is c.151, write the HGVS nomenclature if the bolded and underlined base pairs are inverted: t t t a t t t c c a g T T G *A A T** C T T T C T G T A A C G T T A A C T G C T T C C A G g t a a g c c t g

Answer 58

c.154_156inv or c.154_156invATT